Abstract:

The predation pressures on juvenile Haliotis kamtschatkana, northern abalone, in Barkley Sound. British Columbia, were investigated. Thirty-seven potential predators were tested in the laboratory to determine if they would consume juvenile abalone 1- 25 mm shell length (SL). Six of these potential predators consumed > 10 % of the abalone offered to them and were considered major predators. Natural mortality for juvenile H. kanntschatkana was then estimated by outplanting calcein marked and bee tagged hatchery-reared abalone at field sites. Calcein concentrations between 20 40 mg/L produced clear fluorescent marks for 3- 5 mm SL abalone when exposed to a double calcein marking procedure and abalone > 15 mm SL immersed in calcein for 72 h showed the most distinct marks. Recoveries of outplanted abalone were highest (24%) for 15.1- 20 mm juvenile abalone. I recommend outplanting juvenile abalone larger than 12 mm to increase chances of survivorship in the wild.